Dry-cell lining



Patented May 22, 1928.

UNETE VICTOR YNGVE, OF SOUTH ORANGE, NEW JERSEY, AND WALTER ELWOOD VAIIJ, OF

NEW YORK, N. Y., ASSIGNORS, BY MESNE ASSIGNMENTS, T0 NATIONAL CARBON COMPANY, INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK DRY-CELL LINING.

Io Drawing.

This invention relates to new and useful improvements in making dry cell linings, and particularly to the application of paste to such linings. a

As is well known, in dry cells usually a lining of paper or other bibulous material isprovided between the depolarizing mix and the zinc' electrode to act as a separator between the electrodes of the cell and for the purpose of absorbing a large quantity of water. Inasmuch, however, as such paper lining or cellulose bag is not uniformly porous, it is commonly coated on one or both sides with a paste made of some starchy or gelatinous material.

In assembling dry cells the application of paste to the lining is a relatively slow and expensive operation and the results are not altogether satisfactory, mainly because it is diflicult to in'sure'the uniform distribution of paste throughout the surface of the bag or lining. To remedy this it hast-been suggested to mix the starchy or gelatinous material with the wet paper pulp which is then rolled or compressed into sheet form, thus obtaining a product in which starchy material is uniformly distributed throughout the mass of'the lining. We have found that the efficiency 'of the lining is not improved by such process and that a large percentage of the starch is lost in the white water.

In accordance with the present invention the starchy or gelatinous material is applied to and incorporated in the lining in substantially the following manner? The Wet paper pulp is fed into the paper-making machine in the usual manner, e. g., by being spread in a layer on the continuously movperforated belt or cylinder. The starchy or gelatinous material is then applied on top of the layer of wet paper pulp,

preferably by sprinkling thereon starch suspended'in cold water. Inasmuch as the paper pulp acts as a filter and holds back the particles of starch, a uniform coating of starch. will be deposited on the exposed side of the paper, and the water in which it had been suspended, as well as the water contained in the pulp, is, in the usual manner,

Application filed April 8, 1925. Serial No. 21,183.

eliminated by suction applied to the belt. Some of the starch will penetrate withinthe body of the paper pulp and will benonuniformly distributed therein. However, practically none of the starch will be per-' mitted to escape through the layer of pulp. The'amount of starch and its distribution can be controlled by the amount of starch applied and the place at which it is applied. The manufacture of the paper board is then completed by rolling or compressing the pulp into sheet form, the latter operation may be followed by drying if necessary.

The quantity of starch used depends on the service requirements of the dry cell. The lining will have a uniform coatin of starch which, aided by the starch contained in the body of the lining, will act as an eflicient separator between the electrodes. Furthermore, owing to the .fact that the starch is only slightly hydrolized, it will be in condition to take up a relatively large quantity of water when moistened in the course of assembling the dry cells. Such lining will be of low resistance to the passage of the electric current and when used in a dry cell will give a product of high amperage.

Obviously, the invention is applicable to a variety of paper making processes and the paper pulp or the like-may be molded into other than sheet form, such as cups, which may then be used in dry cells.

What we claim is:

1. The step in the manufacture of dry I cell to the outside surface of the paper and incorporating some of the material=within the paper during the process of the manufacture of the paper.

3. The method of making paper linmg for dry cells which consists in mlxing the paper pulp with water, spreading the pulp, applying a gelatinous or starchy material to the exposed surface of the pulp, and then drying the mixture.

4. The method of making paper lining for dry cells, which consists in spreading the wet paper pulp, sprinkling a suspension of starch in cold Water on the exposed surface of the pulp mass, compressing the pulp and then drying it. I In testimony whereof, we have signed our names to this specification this 31st day of March, 1925.

VICTOR YNGVE. WALTER ELWOOD VAIL. 

